Power conversion systems such as motor drives typically receive AC input power which is converted to an internal DC for subsequent conversion to AC output power for driving a motor or other load. Current source converter type motor drives include a rectifier which converts input AC power from a single or multiphase AC input source to provide DC current to a DC link circuit. An inverter converts the DC link current into single or multiphase AC output power to drive a motor load. Such power conversion systems may be subject to both differential and common mode voltages and currents, which can cause a variety of problems including degradation of the power conversion system and/or the motor load. For instance, motors are susceptible to damage or performance degradation caused by appearance of excessive common mode voltages on the motor leads. Many medium voltage motor drives employ active front end (AFE) rectifiers in order to minimize line-side harmonics using special rectifier switching patterns, as well as a DC link inductor or choke to control common-mode voltage stresses harmful to motor winding insulation. These techniques advantageously mitigate the need for input and/or output transformers resulting in virtually no voltage stress on the motor windings, even if connected through long cables, while saving overall installation cost, size and weight. Thus, medium voltage drives have become a preferred choice over low-voltage drives that typically do not provide active front end switching and therefor require transformers. The benefits of the transformerless operation are also desired in situations where increased drive capability is needed.